1. Technical Field
The present invention relates to a target supporting apparatus for supporting a target onto which a liquid is ejected, a target transporting mechanism having the target supporting apparatus, and a liquid ejecting apparatus having the target supporting apparatus or the target transporting mechanism.
2. Related Art
Generally, ink jet printers (hereinafter, being referred to “a printer”) are well known as liquid ejecting apparatuses for ejecting a liquid onto a target (see, for example, JP-A-2006-150723). The printer disclosed in JP-A-2006-150723 includes a platen (a supporting member) for supporting a continuous form paper (a target) and a recording head (a liquid ejecting head) for ejecting an ink (a liquid) onto the continuous form paper supported on the platen. In addition, a plurality of suction holes penetrates through the platen so that the continuous form paper is sucked and held through the suction holes onto the platen.
Further, when the continuous form paper is transported from the upstream side of the transporting direction to the platen, the transportation of the paper stops for a short time, and the paper is sucked and held onto the platen through the suction holes. Then, the recording head ejects ink onto printing regions of the paper while moving above the paper. Thereafter, when this ejection of the ink onto the paper on the platen is completed, the paper is released from the platen, and then, is transported from the platen to the downstream side of the transportation direction.
Moreover, the platen is provided with a heating unit (e.g., a heater) for heating it. Heat from the heating unit is transferred through the platen to the paper on the platen. As a result, while the ink ejected from the recording head onto the paper is being gradually dried by heat on the platen, the paper is transported from the platen to the downstream side of the transportation direction.
In the printer disclosed in JP-A-2006-150723, as shown in FIGS. 6A to 6C, with respect to the continuous form paper 12 sucked onto a platen 27, a temperature T2 of a region C on a sucking suction hole 44 (hereinafter, being referred to “a noncontact region”) gets lower than a temperature T1 of regions B being directly contact with the heated platen 27 (hereinafter, being referred to “a contact region”) (see FIG. 6A). For this reason, the evaporation level of the solvent in the ink applied onto the paper 12 stopped on the platen 27 is greater in the contact region B in which a rear face of the paper 12 is directly contact with the platen 27 than in the noncontact region C in which the rear face of the paper 12 is positioned on the sucking suction hole 44, thereby causing different drying rates of the ink within the printing regions of the paper 12.
In particular, when the continuous form paper 12 with poor water absorption is used, there are ink flows from the noncontact region C on the sucking suction hole 44 having a lower drying rate to the contact region B on the platen 27 having a higher drying rate. In this way, coloring components which are the solutes contained in the ink as a liquid move from the region C to the region B directly contacted with the platen 27. Further, with appreciating that such an ink flow from the region C to the region B on the continuous form paper 12 arises due to the difference between the temperatures of the regions B, C, even if the platen 27 is not heated, such ink flows may occur. This is because even if the platen is not heated, the temperature of the noncontact region C on the sucking suction hole 44 generally is lower than that of the contact region B.
Accordingly, as shown in FIG. 6B and FIG. 6C, after the drying of the ink is finished, the coloring components get concentrated on the printing region of the paper 12 corresponding to the peripheral region of the sucking suction hole 44, and, hence, coloring levels on the center region and the peripheral region of the suction hole 44 are different from each other, resulting in deteriorating of printing quality (image quality). Further, because the difference in the coloring level occurs between the center region and the peripheral region of the cross-sectional area of the noncontact region C, this difference becomes more pronounced as the cross-sectional area of the suction hole 44 gets larger.